E3D Colorfabb XT issues

I am having real issues getting any decent prints out of my RoStock Max V2.
Pretty sure the actual printer is calibrated correctly.

Not really done much PLA, as its too brittle for my uses. Tried extensively with ABS but suffered real curling and releasing issues.

So, had a go with Colorfabb XT Petg. Seemed pretty good, but needs dialing in..... and that is where I am falling down.
My prints have got steadily worse as I go on. Anyone actually used this stuff? Any recommended settings?

Suffered twice now with a blocked nozzle. The E3D V6 doesn't seem to like retracts over 4.5mm.

If I can't get this sorted, then I think my 3d printing days are almost over.... its the most frustrating hobby ever!

Hi
Tried the nozzle at various. 245 deg seems to be best, but open to suggestions!
This stuff is really gloopy and oozes all over the place. I tried dropping the nozzle temp, but then the print quality went sideways.
Not really having any issues with it sticking to the heated build plate (60 deg).

Because anything shorter than that, and the PETG just oozes all over the shop, strings across the print etc.
1.5mm retraction is pretty short for any filament I would think.
Unfortunately, I think its time to remove the E3D v6 and go back to the stock hotend and try that.